Computer networks comprise a plurality of interconnected networking devices, such as routers, switches and/or computers. The physical connection that allows one networking device to communicate with another networking device is referred to as a link. Links may utilize wired or wireless communication technologies. Data may be communicated between networking devices via the link in groups of binary bits referred to as packets. The rate at which networking devices may communicate data via a link is referred to as link speed.
The task of achieving increasing link speeds is one of the challenges in computer networking technology. Higher link speeds correspond to higher bandwidth and correspondingly higher data rates. In pursing the goal of higher data rates, network architects may face a number of constraints. Such higher, or “cutting edge”, data rates often require components, such as integrated circuit (IC) devices, and interconnect, such as category 6 (Cat6) or Cat7 cabling, which are more expensive than equivalent, more commonly used hardware that may not be capable of achieving the higher data rates. Thus, economic considerations potentially represent one such constraint. Various factors may result in limitations on the speed at which network components may operate, and on the speed at which data may be transferred by the components and/or via interconnect.
As link speeds increase, one operational objective of networking designers may be to incrementally control the bandwidth associated with a link so that bandwidth may be deployed within the network “on demand”. The ability to adjust link bandwidth on demand is referred to as scalability. An objective of scalability is to enable adjustment of link bandwidth dynamically under software control, such as from an operations administration and maintenance (OAM) monitoring terminal.
Networks, which utilize cutting edge technologies, which enable the higher data rates are often used to transport data that have considerable value to the users of the networks, for example for exchange of financial data, or for exchange of large volumes of data between very expensive supercomputer systems. Thus, another potential operational objective is to have the ability to gradually decrease the link bandwidth in the presence of impairments that may occur on the link. This ability to operate the link at a reduced bandwidth, rather than to lose use of the link altogether, is referred to as resiliency.
One approach to overcoming some of the limitations described above is to create a logical high bandwidth link by simultaneously transmitting the data via a plurality of lower bandwidth physical links. This method is often referred to as aggregation. Aggregation creates associations between the logical physical link and a group of physical links. In theory, aggregation enables scalability by increasing logical link bandwidth by increasing the number of associated physical links. Thus, if each physical link has a bandwidth of 10 gigabits/second (Gb), a higher speed logical link may be created by transmitting data via two 10 Gb physical links. In theory, the bandwidth of logical link would be 20 Gb.
Aggregation also enables resiliency through gradual decreasing of logical link bandwidth by decreasing the number of associated physical links. For example, a physical link, which experiences a failure, may be removed from association with the logical link while remaining physical links maintain association with the logical link. Thus, in a logical link associated with two 10 Gb physical links, the logical link bandwidth may be gradually decreased by removing one of the physical links in the association.
Ultimately, communications via a network may be evaluated based upon the rate at which user data are transferred. User data may constitute the portion of data, which are generated by an application that is executing at a networking device. A packet being transferred via a network may comprise user data and additional data which are not user data. Such additional data may be referred to as overhead data. Examples of overhead data include header fields and/or trailer fields, which may be appended to a block of user data to generate the packet. In this regard, the aggregate data transfer rate may measure the rate at which user data including overhead are transferred via a network, where the user data rate may refer to the rate at which user data are transferred via the network. The ratio of user data rate to aggregate data rate may be referred to as an efficiency measure. Thus, the performance of networks may ultimately be evaluated based on criteria related to efficiency.
Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with some aspects of the present invention as set forth in the remainder of the present application with reference to the drawings.